title: (E)-9-(4-Fluoro-styr-yl)-3,3,6,6-tetra-methyl-3,4,5,6,7,9-hexa-hydro-2H-xanthene-1,8-dione.
abstract: In the title compound, C25H27FO3, each of the cyclo-hexenone rings adopts a half-chair conformation, whereas the six-membered pyran ring adopts a flattened boat conformation, with the O and methine C atoms deviating by 0.0769 (15) and 0.196 (2) Å, respectively, from the plane of the other four atoms (r.m.s. deviation = 0.004 Å). The C=C double bond adopts an E conformation. The dihedral angle between the benzene and pyran (all atoms) rings is 89.94 (10)°. In the crystal, weak C-H⋯O hydrogen bonds link the mol-ecules into chains running parallel to the b axis.
authors.affiliation: Center for Neuro-Medicine, Korea Institute of Science & Technology, Hwarangro 14-gil, Seongbuk-gu, Seoul 136-791, Republic of Korea.
authors.forename: Jae Kyun
authors.initials: JK
authors.lastname: Lee
authors.forename: Sun-Joon
authors.initials: SJ
authors.lastname: Min
authors.forename: Yong Seo
authors.initials: YS
authors.lastname: Cho
authors.forename: Joo Hwan
authors.initials: JH
authors.lastname: Cha
authors.forename: Sung Ok
authors.initials: SO
authors.lastname: Won